Refrigeration "The Big Chill"

REFRIGERATION
The Big Chill
I
By Green Brett
love my mother-in-law, I really do. But how were we to
explain that her new grandchild would be snuggling up
with our trusty steel Engel
refrigerator box in the no-longerspare quarter berth?
“Oh, don’t worry, the baby will
sleep with us for the first few weeks.”
Or, “We’ll just get rid of the Engel
and lug blocks of ice for the boat’s
icebox down the snowy dock,” (along
with our four-year-old daughter,
new baby, groceries and stroller).
Or, “Sorry, you can’t visit right
now,” (which was not a good option
for several reasons). My mother-inlaw might not even like me unless
something was done immediately.
Timing is
everything
during
Lyra’s
refrigeration
installation
54
She was coming up from Florida to
stay with us for the baby shower in
less than a week and the Engel was
still using the baby’s (and for now
our spare) bunk.
SETTING THE SCENE
We have a nice icebox on Lyra, but
the previous owner had pulled out
the engine-driven Sea Frost refrigeration system. For the first month
that we lived aboard, we lugged ice
down to the boat twice a week, but
the melt goop made a stinky mess in
the bilge.
On our annual trip to see the family, we recovered our Engel refrigerator box from an attic. It worked
well enough; the wind generator
Blue Water Sailing • May 2010
REFRIGERATION
and solar panel nearly kept up with
its power draw. Unfortunately, its
relatively small interior volume
didn’t make up for all the space it
took up in the spare bunk. With a
baby on the way, it would have to go.
We needed refrigeration for Lyra’s
icebox.
porous bronze heat sinks that are installed much like a through-hull. The
refrigerant circulates through the
keel cooler and bleeds the heat off
into the water. Even in tropical waters, keel coolers remove heat more
efficiently than an air-cooled unit
will. More and more cruising boats
are going to a hybrid system, where
RESEARCHING OUR NEEDS
the air-cooler is turned on only when
The first order of business was to
the boat is out of the water. This is
figure out what we had to work with.
the option that we chose.
According to the original owner of
As a direct result of choosing
our boat, the icebox had four inches
the less powerful, battery-driven
of insulating foam and required one
compressor, we chose to install an
hour of engine run
evaporator rather than a
time each day to keep
cold plate. Cold plates are
MARINE REFRIGERATION COMPONENTS
the box cool and make
designed around massive,
Stated simply, marine refrigeration systems have
two trays of ice cubes.
engine-driven compresthe following parts:
From this, we inferred
sors. Their brine solution
• Compressor - This pressurizes the refrigerant gas returning
from the evaporator and also raises its temperature.
that the icebox was
has a low freezing point
• Condenser - This can be a radiator with a fan, a pipe with
reasonably well insuand can “store” a great
seawater pumped around it, or a Keel Cooler. It reduces the
lated.
deal of cold, much like
temperature of the gas and condenses it into a liquid.
We would also need
a battery. With a 12-volt
• Metering device - Can be capillary tube or expansion valve.
to account for the
system, it is much more
Separates the high and low pressure sides of the system and
volume. Using this
efficient to run a smaller,
feeds liquid refrigerant into the evaporator.• Thermostat—this
sets the temperature and tells the compressor when to run
formula—length X
lower power draw com• Evaporator - Can be “Flat” evaporator or holding plate. A
height X width—and
pressor. This matches up
holding plate will “sink” heat (it stays cold) for long periods of
fudging a bit off for
better with an evaporator
time using a brine solution that has a low freezing point, but
the turn of the hull, we
than with cold plates.
the compressor must run for extended periods. All evaporators
came up with about 10
The aluminum body of
get cold when the liquid refrigerant boils (evaporates) in the
cubic feet of air space
an evaporator is better
evaporator at very low temperatures when exposed to the low
pressure side of the compressor.
to cool.
at transferring heat than
Next, we had to
the stainless steel of
choose the system that
cold plates. An evaporawould work best for our needs. We
refrigerator draw.
tor is also typically configured as a
live at anchor in the summers and
If we chose to go with an airrectangular container—the interior
on a dock with shore power in the
cooled system, we would need to
is an instant freezer. If more freezer
winter. Our eventual plans include
locate the compressor/condenser
space is desired, a vertical partition can
cruising in the tropics. We are trying in a location where there would be
be added in the icebox to create a “spill
to minimize our engine run time by
cool air let in and a place for hot
over,” exactly as one would with a cold
using solar and our KISS wind genair to exit. The nice thing about an
plate system. If we had a separate
erator to keep up with our needs.
air-cooled system is that it can be
freezer box, the evaporator would still
If we reinstalled an engine-driven
used even if the boat is hauled out
get cold enough to do the job.
compressor, a second compressor
of the water. They are, however, less
There are two downsides to inwould be needed if we wanted to
efficient and slightly noisier than a
stalling an evaporator versus a cold
keep the icebox cold with shore
keel-cooled system. A water-cooled
plate. The aluminum body of the
power. Our venerable diesel may be
system is more efficient than an
evaporator is much less durable than
reliable and push the boat around
air-cooled system, but it requires
the stainless steel of the cold plate.
effectively, but nobody would call it
more electricity to run the required
This results in a roughly 10-year life
quiet. Why wake a sleeping baby to
circulating pump. Keel coolers are
span and a “no ice pick” policy for
www.bwsailing.com
keep the icebox cold? This was not a
good option for us.
If we installed a 12-volt compressor, we would be able to use any
green power that we could harvest.
Certainly there would be days when
there wasn’t enough sun or wind
to keep up the batteries, but at least
we wouldn’t be stuck running the
engine for an hour every day. As
long as we left the batteries with a
full charge, a 12-volt system would
also give us the freedom to leave
the boat unattended for as long as
our batteries could keep up with the
55
REFRIGERATION
Top, the complete package; bottom, keel cooler and an old
through hull. Opposite, fresh paint and a shiny icebox
the evaporator, while a cold plate
will last indefinitely and is more
likely to survive being repeatedly
stabbed with sharp objects. We decided that $300 now and again in 10
years was an acceptable price to pay
for an evaporator. An appropriatelysized cold plate would cost much
more and we would need to alter
our icebox configuration to make the
freezer space we desired.
We chose to go with a digital
thermostat rather than the mechanical one, as the digital unit measures
the temperature in the icebox itself
rather than the temperature of the
56
evaporator. When coupled with a
Smart Speed Control-capable compressor, we would have extremely
stable temperatures in the icebox.
The mechanical thermosat costs less
than the digital version and can be
used with the Smart Speed Control
unit.
FRIGOBOAT
After much research, we decided
to use Frigoboat (www.frigoboat.
com) as our source of refrigerant
systems. Their website is clearly
written and simple to navigate, their
prices are competitive, and there is
excellent resource material to answer
any questions that you have about
designing your system.
Once we had an informed idea
of what we wanted for our system,
we picked up the telephone and
called Frigoboat. They made a few
suggestions to fine tune our system
and shipped the order the same
day. Customer service during the
installation was immediate and wellinformed. In fact, our entire experience with Frigoboat was top-notch.
If you would like to see operational
systems, the company has a booth at
most boat shows.
Blue Water Sailing • May 2010
REFRIGERATION
INSTALLATION
The first order of business was to
prepare the area. I had already put
two coats of Sherwin-Williams Tile
Clad epoxy paint on the interior of the
icebox and replaced the original lid
seal with two strips of window seal
(available at your local hardware store).
Once we had the system components, we verified that the allocated
space for each item was proper.
The biggest change in the original
plan was to convert the verticallymounted evaporator to a horizontal
mount. This would give us more usable space and leave the full aperture
of the icebox lid available to us for
loading large items. The conversion
consists of adding a formed plastic
door with a simple bungee that acts
as a hinge.
Our icebox extends into the aft
head as counter space, so we installed the Capri 50-SSC and the
Smart Speed Controller under the
aft head sink. This is four feet away
from the through-hull location for
the keel cooler (it must be less than
six feet) and right next to the icebox
wall. From there, it was a simple
matter to install the 340H evaporator
and run the copper tubing through
the icebox wall and down to the
compressor. The only tools needed
were a saber saw, drill, drill bits, a
one-and-a-half-inch hole saw and
screwdrivers. The one-and-a-half-inch
hole allows the tubing and fittings to
fit through a single hole in the icebox
wall and is also the size of the keel
cooler through-hull. The hole in the
icebox is quickly resealed with a can
of expanding foam, also available at
your local hardware store. I also cut
a hole though the bulkhead so that the
thermometer could display in the galley. Within five hours, the system was
up and running as an air-cooled unit.
Enter: MY MOTHER-IN-LAW.
Yes, I was attempting to complete
the refrigeration installation in time
for her visit (remember, she needed
to sleep in the spare bunk that had
been the home of our Engel). I am
not sure if her first impression
of the project was necessarily the
one I was going for, as the interior
looked remarkably like the boat had
suffered a recent knockdown, with
tools scattered across the entire living space and displaced items from
the work areas in question likewise
haphazardly stacked in every available nook and cranny. She was great
about it and we did end up with cold
food and space for her to sleep that
Unit
Frigoboat Description
Notes
Frigoboat Cost
Compressor
Capri 50-SSC with Smart
Speed Control
The keel cooler can be
added in line
$1,271.00
Keel Cooler
Keel Cooler Stud-Mounted
Condenser with Zinc
The puck can do
double duty as an SSB
ground plate
$659.75
Evaporator
340H Evaporator - 15”w x
6”h x 11.5”d
Added lid kit so it
could be installed
horizontally
$441.75
Thermostat
Coastal Digital Fahrenheit
12v
Necessary to operate
the Smart Speed
Controller
$125.00
www.bwsailing.com
57
REFRIGERATION
Big sis Caitlyn, the author and new
addition Juliana enjoying the fruits of
Green’s labor; bottom, the finished
product
night. She even got to help decorate
the space for the coming baby.
We ran the system in the aircooled configuration for two weeks
before hauling the boat to install
the keel cooler. Daily temperatures
were typically around 85 degrees
and the water temperature was 78.
We estimate that our 10 cubic foot
icebox used 22 amp hours each day.
The cooling fan is audible, but not
annoyingly so.
Adding the keel cooler was a
relatively simple process. We hauled
the boat at 9 a.m., and the puck was
installed by 10:30 a.m. Since it was
58
bedded with 3M
Fast Cure 5200,
we let it set until
just after lunch
before relaunching. We had
opted to get the
stud-type keel
cooler versus the threaded version,
which allowed me to do the installation quickly and by myself. Since the
quick connectors do not lose refrigerant when they are disconnected, it
was a simple matter to connect the
keel cooler inline with the air-cooled
system.
With the air-cooling fan disconnected, we estimate that there was a
25 to 30 percent increase in efficiency. Also, the system became nearly
silent in operation once we turned
off the air-cooling fan. If power
consumption is a concern, the keel
cooler is a must.
After five months of continuous
live-aboard use, we remain completely
happy with the entire refrigeration
system. The only change that we have
made is to apply some plastic foam
with contact cement to the bottom of
our evaporator. This makes the interior
freezer area colder and keeps the rest
of the box at 34 degrees. We routinely
keep vegetables such as lettuce fresh
for two weeks and have ice cream
when we want it. We know that the
system works great in both summer
and winter conditions, and are confident that it will also function properly
in a tropical climate.
Green Brett grew up living aboard
a cruising sailboat. He and his wife,
Jen, are currently based in Newport,
R.I., and are raising their daughters
aboard Lyra, their Reliance 44. You
can wish them luck at jen@bwsailing.
com
Blue Water Sailing • May 2010
I’d just like to say that …………. “I must say, this is a most efficient and very excellent refrigeration system. Quiet, light on amps, and very effective at cooling/freezing.” Chris Goodfellow ************************************************************************ “Well, I finally got the refer installed and it works great! I especially liked the way the gas connectors work. Obviously a great deal of work went into your instructions. They were very useful. Thank you so much for your great assistance throughout these birth pains. Great technical support is what makes or breaks many vendors, but unfortunately most don't realize that until it is too late.” Mike Dietz ************************************************************************ “It’s probably not that often that good products gets the recognition they deserve but I wanted not to let good praise go by without passing it on. Our production and sales team here love your system and found it to be user friendly and an absolute winner for our production installation. From all of the Catalina team here "Thanks for sending good, easy to install units.” Bob DeFilippo – Catalina Yachts ************************************************************************ “Many thanks for your prompt and honest response. It's obvious to me that you care more with the reputation of your product than in doing a quick single sale.” Oscar Ernst ************************************************************************ “Almost every piece of equipment on the boat has needed some repair or attention over the last year except my Frigoboat system. It sure is nice to know that, at the end of the day when I'm tired and frustrated, I can depend on having a cold beer. Thanks.” Bob Willmann ‐ S/V Viva ************************************************************************ “The Frigo unit is absolutely unbeatable and a nice piece of engineering on top of that.” Alan Sugarman ************************************************************************ “We thank you very much for all your support. It is helpful and comforting to know that there is someone there after the sale!” Nancy and Bob Bush ************************************************************************ “I've had a Frigoboat keel cooler system installed on my Islander 36 for about three years now. It's been the single greatest upgrade I've made to the boat ‐‐ easy to install, quiet, efficient, just works flawlessly.” Eric Lyons ‐ s/v Pearl, Islander 36